Data Network Fundamentals

This blog I would like to give a glance about Data network fundaments.  The different between NAS and SAN, and how iSCSI, SAS, and FC work within SAS systems. In addition, simple explanation of how to data networking relevance the file storage, block storage, high availability (HA), high-performance computing (HPC) .

Data storage and data networking

Data storage:

  • Data over time
  • Information repository
  • Capacity

Data Network:

  • Data over distance
  • Information movement
  • Speed
  • Hubs and switches


NAS and SAN: Access

NAS = File Access

  • Files managed within the NAS system
  • Management simplified


SAN = Block access

  • Files managed outside the SAN system
  • Configured flexible
  • Performance high



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SAN connection: iSCSI, SAS, and FC


  • Is an IP-based standard that is the primary alternative to FC
  • Is less expensive (uses standard cables and switches)
  • Can send signals longer distances
  • Is a client-server protocol including initiator is the client and target are the servers
  • Works with servers that use iSCSI software initiators or host bus adapter (HBA) cards for connection


Uses aerial cable and carries SCSI packets

Is inexpensive and more reliable than iSCSI

Has a limited range and provides a limited number of connections



  • Very reliable
  • Scalable
  • Flexible

Use cases

  • Designed for supercomputers
  • Now used in most enterprise storage application

FC: Topologies and Zoning


  • FC –P2P (point to point)
  • FC-AL (arbitrated loop)
  • FC-SW (switch fabric): Single or dual

Zoning: Hard versus soft


Brief of File and Block storage, High availability, and high-performance computing 

File storage versus Block Storage

Block storage:

  • Treats data as standardised chunks of data
  • Provide greater flexibility and higher performance

File storage

  • Handles data in terms of files
  • Easier and simple to deploy

What is the High Availability?

  • Ultimate goal – all data available at all times
  • Method –redundancy
  • Measurement –nines -99% = two nine, 99.99% = four nines

High-Performance computing:  Exceptional large system for example weather forecasting and climate research, oil and gas exploration, and molecular modelling


  • Small configuration changes produce large benefits
  • Performance is measured in FLOPS (floating point operations per second )

Question: What is the best data network solution for the medium sales based company?

Answer:  For the medium sales based company where employees need to shared file which may be contained the sales figures of different interval or might be client profile. The best solution would be this type of company NAS solutions because NAS is easier to implement and simple to managing and cost effective for medium size organisation. NAS is the best solution for file sharing in the local area network.